// 抽象类

export {}  // 确保跟其它示例没有成员冲突

abstract class Animal {
    eat (food: string): void {
        console.log(`呼噜呼噜的吃：${food}`)
    }

    abstract run (distance: number): void
}

class Dog extends Animal {
    run(distance: number): void {
        console.log('四脚爬行', distance)
    }
}

const d = new Dog()
d.eat('哈哈');
d.run(100)